Implemented directory caching. No more waiting for disk to spin up while

browsing when cache is enabled (system -> disk -> enable directory
cache). Cache building on boot is transparent except the first boot.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7588 a1c6a512-1295-4272-9138-f99709370657

firmware/common/dircache.c

@@ -0,0 +1,792 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2005 by Miika Pekkarinen
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+/* TODO:
+   - Allow cache live updating while transparent rebuild is running.
+   - Fix this to work with simulator (opendir & readdir) again.
+*/
+
+#include "config.h"
+
+#ifdef HAVE_DIRCACHE
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdbool.h>
+#include "dir.h"
+#include "debug.h"
+#include "atoi.h"
+#include "system.h"
+#include "logf.h"
+#include "dircache.h"
+#include "thread.h"
+#include "kernel.h"
+#include "usb.h"
+#include "file.h"
+
+/* Queue commands. */
+#define DIRCACHE_BUILD 1
+
+extern char *audiobuf;
+
+#define MAX_OPEN_DIRS 8
+DIRCACHED opendirs[MAX_OPEN_DIRS];
+
+static struct dircache_entry *fd_bindings[MAX_OPEN_FILES];
+static struct dircache_entry *dircache_root;
+
+static bool dircache_initialized = false;
+static bool thread_enabled = false;
+static unsigned long allocated_size = DIRCACHE_LIMIT;
+static unsigned long dircache_size = 0;
+static unsigned long reserve_used = 0;
+static char dircache_cur_path[MAX_PATH];
+
+static struct event_queue dircache_queue;
+static long dircache_stack[(DEFAULT_STACK_SIZE + 0x800)/sizeof(long)];
+static const char dircache_thread_name[] = "dircache";
+
+/* --- Internal cache structure control functions --- */
+static struct dircache_entry* allocate_entry(void)
+{
+    struct dircache_entry *next_entry;
+    
+    if (dircache_size > allocated_size - MAX_PATH*2)
+    {
+        logf("size limit reached");
+        return NULL;
+    }
+    
+    next_entry = (struct dircache_entry *)((char *)dircache_root+dircache_size);
+    dircache_size += sizeof(struct dircache_entry);
+    next_entry->name_len = 0;
+    next_entry->d_name = NULL;
+    next_entry->down = NULL;
+    next_entry->next = NULL;
+
+    return next_entry;
+}
+
+static struct dircache_entry* dircache_gen_next(struct dircache_entry *ce)
+{
+    struct dircache_entry *next_entry;
+
+    next_entry = allocate_entry();
+    ce->next = next_entry;
+    
+    return next_entry;
+}
+
+static struct dircache_entry* dircache_gen_down(struct dircache_entry *ce)
+{
+    struct dircache_entry *next_entry;
+
+    next_entry = allocate_entry();
+    ce->down = next_entry;
+    
+    return next_entry;
+}
+
+/* This will eat ~30 KiB of memory!
+ * We should probably use that as additional reserve buffer in future. */
+#define MAX_SCAN_DEPTH 16
+static struct travel_data dir_recursion[MAX_SCAN_DEPTH];
+
+static int dircache_scan(struct travel_data *td)
+{
+    while ( (fat_getnext(td->dir, &td->entry) >= 0) && (td->entry.name[0]))
+    {
+        if (thread_enabled)
+        {
+            /* Stop if we got an external signal. */
+            if (!queue_empty(&dircache_queue))
+                return -6;
+            yield();
+        }
+            
+        if (!strcmp(".", td->entry.name) ||
+             !strcmp("..", td->entry.name))
+        {
+            continue;
+        }
+                
+        td->ce->attribute = td->entry.attr;
+        td->ce->name_len = MIN(254, strlen(td->entry.name)) + 1;
+        td->ce->d_name = ((char *)dircache_root+dircache_size);
+        td->ce->startcluster = td->entry.firstcluster;
+        td->ce->size = td->entry.filesize;
+        td->ce->wrtdate = td->entry.wrtdate;
+        td->ce->wrttime = td->entry.wrttime;
+        memcpy(td->ce->d_name, td->entry.name, td->ce->name_len);
+        dircache_size += td->ce->name_len;
+        
+        if (td->entry.attr & FAT_ATTR_DIRECTORY)
+        {
+            
+            td->down_entry = dircache_gen_down(td->ce);
+            if (td->down_entry == NULL)
+                return -2;
+            
+            td->pathpos = strlen(dircache_cur_path);
+            strncpy(&dircache_cur_path[td->pathpos], "/", MAX_PATH - td->pathpos - 1);
+            strncpy(&dircache_cur_path[td->pathpos+1], td->entry.name, MAX_PATH - td->pathpos - 2);
+
+            td->newdir = *td->dir;
+            if (fat_opendir(IF_MV2(volume,) &td->newdir,
+                td->entry.firstcluster, td->dir) < 0 )
+            {
+                return -3;
+            }
+
+            td->ce = dircache_gen_next(td->ce);
+            if (td->ce == NULL)
+                return -4;
+            
+            return 1;
+        }
+        
+        td->ce->down = NULL;
+        td->ce = dircache_gen_next(td->ce);
+        if (td->ce == NULL)
+            return -5;
+    }
+
+    return 0;
+}
+
+/* Recursively scan the hard disk and build the cache. */
+static int dircache_travel(struct fat_dir *dir, struct dircache_entry *ce)
+{
+    int depth = 0;
+    int result;
+
+    dir_recursion[0].dir = dir;
+    dir_recursion[0].ce = ce;
+    
+    do {
+        //logf("=> %s", dircache_cur_path);
+        result = dircache_scan(&dir_recursion[depth]);
+        switch (result) {
+            case 0: /* Leaving the current directory. */
+                depth--;
+                if (depth >= 0)
+                    dircache_cur_path[dir_recursion[depth].pathpos] = '\0';
+                break ;
+
+            case 1: /* Going down in the directory tree. */
+                depth++;
+                if (depth >= MAX_SCAN_DEPTH)
+                {
+                    logf("Too deep directory structure");
+                    return -2;
+                }
+                    
+                dir_recursion[depth].dir = &dir_recursion[depth-1].newdir;
+                dir_recursion[depth].ce = dir_recursion[depth-1].down_entry;
+                break ;
+            
+            default:
+                logf("Scan failed");
+                logf("-> %s", dircache_cur_path);
+                return -1;
+        }
+    } while (depth >= 0) ;
+    
+    return 0;
+}
+
+static struct dircache_entry* dircache_get_entry(const char *path,
+        bool get_before, bool only_directories)
+{
+    struct dircache_entry *cache_entry, *before;
+    char namecopy[MAX_PATH];
+    char* part;
+    char* end;
+
+    strncpy(namecopy, path, sizeof(namecopy) - 1);
+    cache_entry = dircache_root;
+    before = NULL;
+    
+    for ( part = strtok_r(namecopy, "/", &end); part;
+          part = strtok_r(NULL, "/", &end)) {
+
+        /* scan dir for name */
+        while (1)
+        {
+            if (cache_entry == NULL)
+            {
+                return NULL;
+            }
+            else if (cache_entry->name_len == 0)
+            {
+                cache_entry = cache_entry->next;
+                continue ;
+            }
+
+            if (!strcasecmp(part, cache_entry->d_name))
+            {
+                before = cache_entry;
+                if (cache_entry->down || only_directories)
+                    cache_entry = cache_entry->down;
+                break ;
+            }
+
+            cache_entry = cache_entry->next;
+        }
+    }
+
+    if (get_before)
+        cache_entry = before;
+        
+    return cache_entry;
+}
+
+#if 0
+int dircache_load(const char *path)
+{
+    struct dircache_maindata maindata;
+    int bytes_read;
+    int fd;
+        
+    if (dircache_initialized)
+        return -1;
+        
+    logf("Loading directory cache");
+    dircache_size = 0;
+    
+    fd = open(path, O_RDONLY);
+    if (fd < 0)
+        return -2;
+        
+    bytes_read = read(fd, &maindata, sizeof(struct dircache_maindata));
+    if (bytes_read != sizeof(struct dircache_maindata)
+        || (long)maindata.root_entry != (long)audiobuf
+        || maindata.size <= 0)
+    {
+        close(fd);
+        return -3;
+    }
+
+    dircache_root = (struct dircache_entry *)audiobuf;
+    bytes_read = read(fd, dircache_root, MIN(DIRCACHE_LIMIT, maindata.size));
+    close(fd);
+    
+    if (bytes_read != maindata.size)
+        return -6;
+
+    /* Cache successfully loaded. */
+    dircache_size = maindata.size;
+    logf("Done, %d KiB used", dircache_size / 1024);
+    dircache_initialized = true;
+    memset(fd_bindings, 0, sizeof(fd_bindings));
+    
+    /* We have to long align the audiobuf to keep the buffer access fast. */
+    audiobuf += (long)((dircache_size & ~0x03) + 0x04);
+    audiobuf += DIRCACHE_RESERVE;
+
+    return 0;
+}
+
+int dircache_save(const char *path)
+{
+    struct dircache_maindata maindata;
+    int fd;
+    unsigned long bytes_written;
+
+    remove(path);
+    
+    while (thread_enabled)
+        sleep(1);
+        
+    if (!dircache_initialized)
+        return -1;
+
+    logf("Saving directory cache");
+    fd = open(path, O_WRONLY | O_CREAT);
+
+    maindata.magic = DIRCACHE_MAGIC;
+    maindata.size = dircache_size;
+    maindata.root_entry = dircache_root;
+
+    /* Save the info structure */
+    bytes_written = write(fd, &maindata, sizeof(struct dircache_maindata));
+    if (bytes_written != sizeof(struct dircache_maindata))
+    {
+        close(fd);
+        return -2;
+    }
+
+    /* Dump whole directory cache to disk */
+    bytes_written = write(fd, dircache_root, dircache_size);
+    close(fd);
+    if (bytes_written != dircache_size)
+        return -3;
+
+    return 0;
+}
+#endif /* #if 0 */
+
+static int dircache_do_rebuild(void)
+{
+    struct fat_dir dir;
+    
+    if ( fat_opendir(IF_MV2(volume,) &dir, 0, NULL) < 0 ) {
+        logf("Failed opening root dir");
+        return -3;
+    }
+
+    //return -5;
+/*    dir = opendir("/");
+    if (dir == NULL)
+    {
+        logf("failed to open rootdir");
+        return -1;
+}*/
+
+    memset(dircache_cur_path, 0, MAX_PATH);
+    dircache_size = sizeof(struct dircache_entry);
+
+    cpu_boost(true);
+    if (dircache_travel(&dir, dircache_root) < 0)
+    {
+        logf("dircache_travel failed");
+        cpu_boost(false);
+        dircache_size = 0;
+        return -2;
+    }
+    cpu_boost(false);
+
+    logf("Done, %d KiB used", dircache_size / 1024);
+    dircache_initialized = true;
+    
+    if (thread_enabled)
+    {
+        if (allocated_size - dircache_size < DIRCACHE_RESERVE)
+            reserve_used = DIRCACHE_RESERVE - (allocated_size - dircache_size);
+    }
+    else
+    {
+        /* We have to long align the audiobuf to keep the buffer access fast. */
+        audiobuf += (long)((dircache_size & ~0x03) + 0x04);
+        audiobuf += DIRCACHE_RESERVE;
+        allocated_size = dircache_size + DIRCACHE_RESERVE;
+    }
+    
+    return 1;
+}
+
+static void dircache_thread(void)
+{
+    struct event ev;
+
+    while (1)
+    {
+        queue_wait(&dircache_queue, &ev);
+
+        switch (ev.id)
+        {
+            case DIRCACHE_BUILD:
+                thread_enabled = true;
+                dircache_do_rebuild();
+                thread_enabled = false;
+                break ;
+                
+#ifndef SIMULATOR
+            case SYS_USB_CONNECTED:
+                usb_acknowledge(SYS_USB_CONNECTED_ACK);
+                usb_wait_for_disconnect(&dircache_queue);
+                break ;
+#endif
+        }
+    }
+}
+
+int dircache_build(int last_size)
+{
+    if (dircache_initialized)
+        return -3;
+
+    while (thread_enabled)
+        sleep(1);
+        
+    logf("Building directory cache");
+    if (dircache_size > 0)
+    {
+        allocated_size = dircache_size + (DIRCACHE_RESERVE-reserve_used);
+        thread_enabled = true;
+        queue_post(&dircache_queue, DIRCACHE_BUILD, 0);
+        return 2;
+    }
+    else
+    {
+        dircache_root = (struct dircache_entry *)audiobuf;
+        dircache_size = 0;
+    }
+
+    if (last_size > DIRCACHE_RESERVE && last_size < DIRCACHE_LIMIT)
+    {
+        allocated_size = last_size + DIRCACHE_RESERVE;
+        
+        /* We have to long align the audiobuf to keep the buffer access fast. */
+        audiobuf += (long)((allocated_size & ~0x03) + 0x04);
+        thread_enabled = true;
+
+        /* Start a transparent rebuild. */
+        queue_post(&dircache_queue, DIRCACHE_BUILD, 0);
+        return 3;
+    }
+
+    /* Start a non-transparent rebuild. */
+    return dircache_do_rebuild();
+}
+
+void dircache_init(void)
+{
+    int i;
+    
+    memset(opendirs, 0, sizeof(opendirs));
+    for (i = 0; i < MAX_OPEN_DIRS; i++)
+    {
+        opendirs[i].secondary_entry.d_name = audiobuf;
+        audiobuf += MAX_PATH;
+    }
+    
+    queue_init(&dircache_queue);
+    create_thread(dircache_thread, dircache_stack,
+                sizeof(dircache_stack), dircache_thread_name);
+}
+
+bool dircache_is_enabled(void)
+{
+    return dircache_initialized;
+}
+
+int dircache_get_cache_size(void)
+{
+    if (!dircache_is_enabled())
+        return 0;
+    
+    return dircache_size;
+}
+
+void dircache_disable(void)
+{
+    int i;
+    
+    while (thread_enabled)
+        sleep(1);
+    dircache_initialized = false;
+
+    for (i = 0; i < MAX_OPEN_DIRS; i++)
+        opendirs[i].busy = false;
+}
+
+/* --- Directory cache live updating functions --- */
+static struct dircache_entry* dircache_new_entry(const char *path, int attribute)
+{
+    struct dircache_entry *entry;
+    char basedir[MAX_PATH];
+    char *new;
+    long last_cache_size = dircache_size;
+
+    strncpy(basedir, path, sizeof(basedir)-1);
+    new = strrchr(basedir, '/');
+    if (new == NULL)
+    {
+        logf("error occurred");
+        dircache_initialized = false;
+        return NULL;
+    }
+
+    *new = '\0';
+    new++;
+
+    entry = dircache_get_entry(basedir, false, true);
+    if (entry == NULL)
+    {
+        logf("basedir not found!");
+        dircache_initialized = false;
+        return NULL;
+    }
+
+    if (reserve_used + 2*sizeof(struct dircache_entry) + strlen(new)+1
+        >= DIRCACHE_RESERVE)
+    {
+        logf("not enough space");
+        dircache_initialized = false;
+        return NULL;
+    }
+    
+    while (entry->next != NULL)
+        entry = entry->next;
+
+    if (entry->name_len > 0)
+        entry = dircache_gen_next(entry);
+
+    if (entry == NULL)
+    {
+        dircache_initialized = false;
+        return NULL;
+    }
+        
+    entry->attribute = attribute;
+    entry->name_len = MIN(254, strlen(new)) + 1;
+    entry->d_name = ((char *)dircache_root+dircache_size);
+    entry->startcluster = 0;
+    entry->wrtdate = 0;
+    entry->wrttime = 0;
+    entry->size = 0;
+    memcpy(entry->d_name, new, entry->name_len);
+    dircache_size += entry->name_len;
+
+    if (attribute & ATTR_DIRECTORY)
+    {
+        logf("gen_down");
+        dircache_gen_down(entry);
+    }
+        
+    reserve_used += dircache_size - last_cache_size;
+
+    return entry;
+}
+
+void dircache_bind(int fd, const char *path)
+{
+    struct dircache_entry *entry;
+    
+    if (!dircache_initialized)
+        return ;
+
+    logf("bind: %d/%s", fd, path);
+    entry = dircache_get_entry(path, false, false);
+    if (entry == NULL)
+    {
+        logf("not found!");
+        dircache_initialized = false;
+        return ;
+    }
+
+    fd_bindings[fd] = entry;
+}
+
+void dircache_update_filesize(int fd, long newsize)
+{
+    if (!dircache_initialized || fd < 0)
+        return ;
+
+    fd_bindings[fd]->size = newsize;
+}
+
+void dircache_mkdir(const char *path)
+{ /* Test ok. */
+    if (!dircache_initialized)
+        return ;
+        
+    logf("mkdir: %s", path);
+    dircache_new_entry(path, ATTR_DIRECTORY);
+}
+
+void dircache_rmdir(const char *path)
+{ /* Test ok. */
+    struct dircache_entry *entry;
+    
+    if (!dircache_initialized)
+        return ;
+        
+    logf("rmdir: %s", path);
+    entry = dircache_get_entry(path, true, true);
+    if (entry == NULL)
+    {
+        logf("not found!");
+        dircache_initialized = false;
+        return ;
+    }
+
+    entry->down = NULL;
+    entry->name_len = 0;
+}
+
+/* Remove a file from cache */
+void dircache_remove(const char *name)
+{ /* Test ok. */
+    struct dircache_entry *entry;
+    
+    if (!dircache_initialized)
+        return ;
+        
+    logf("remove: %s", name);
+    
+    entry = dircache_get_entry(name, false, false);
+
+    if (entry == NULL)
+    {
+        logf("not found!");
+        dircache_initialized = false;
+        return ;
+    }
+    
+    entry->name_len = 0;
+}
+
+void dircache_rename(const char *oldpath, const char *newpath)
+{ /* Test ok. */
+    struct dircache_entry *entry, *newentry;
+    
+    if (!dircache_initialized)
+        return ;
+        
+    logf("rename: %s->%s", oldpath, newpath);
+    entry = dircache_get_entry(oldpath, true, false);
+    if (entry == NULL)
+    {
+        logf("not found!");
+        dircache_initialized = false;
+        return ;
+    }
+
+    /* Delete the old entry. */
+    entry->name_len = 0;
+
+    newentry = dircache_new_entry(newpath, entry->attribute);
+    if (newentry == NULL)
+    {
+        dircache_initialized = false;
+        return ;
+    }
+
+    //newentry->down = entry->down;
+    //entry->down = 0;
+    
+    newentry->size = entry->size;
+    newentry->startcluster = entry->startcluster;
+    newentry->wrttime = entry->wrttime;
+    newentry->wrtdate = entry->wrtdate;
+}
+
+void dircache_add_file(const char *path)
+{
+    if (!dircache_initialized)
+        return ;
+        
+    logf("add file: %s", path);
+    dircache_new_entry(path, 0);
+}
+
+DIRCACHED* opendir_cached(const char* name)
+{
+    struct dircache_entry *cache_entry;
+    int dd;
+    DIRCACHED* pdir = opendirs;
+
+    if ( name[0] != '/' )
+    {
+        DEBUGF("Only absolute paths supported right now\n");
+        return NULL;
+    }
+
+    /* find a free dir descriptor */
+    for ( dd=0; dd<MAX_OPEN_DIRS; dd++, pdir++)
+        if ( !pdir->busy )
+            break;
+
+    if ( dd == MAX_OPEN_DIRS )
+    {
+        DEBUGF("Too many dirs open\n");
+        errno = EMFILE;
+        return NULL;
+    }
+
+    if (!dircache_initialized)
+    {
+        pdir->regulardir = opendir(name);
+        if (!pdir->regulardir)
+            return NULL;
+        
+        pdir->busy = true;
+        return pdir;
+    }
+    
+    pdir->busy = true;
+    pdir->regulardir = NULL;
+    cache_entry = dircache_get_entry(name, false, true);
+    pdir->entry = cache_entry;
+
+    if (cache_entry == NULL)
+    {
+        pdir->busy = false;
+        return NULL;
+    }
+
+    return pdir;
+}
+
+struct dircache_entry* readdir_cached(DIRCACHED* dir)
+{
+    struct dirent *regentry;
+    struct dircache_entry *ce;
+    
+    if (!dir->busy)
+        return NULL;
+
+    if (!dircache_initialized)
+    {
+        if (dir->regulardir == NULL)
+            return NULL;
+        regentry = readdir(dir->regulardir);
+        if (regentry == NULL)
+            return NULL;
+        
+        strncpy(dir->secondary_entry.d_name, regentry->d_name, MAX_PATH-1);
+        dir->secondary_entry.size = regentry->size;
+        dir->secondary_entry.startcluster = regentry->startcluster;
+        dir->secondary_entry.attribute = regentry->attribute;
+        dir->secondary_entry.wrttime = regentry->wrttime;
+        dir->secondary_entry.wrtdate = regentry->wrtdate;
+        dir->secondary_entry.next = NULL;
+        
+        return &dir->secondary_entry;
+    }
+        
+    do {
+        if (dir->entry == NULL)
+            return NULL;
+
+        ce = dir->entry;
+        if (ce->name_len == 0)
+            dir->entry = ce->next;
+    } while (ce->name_len == 0) ;
+
+    dir->entry = ce->next;
+
+    //logf("-> %s", ce->name);
+    return ce;
+}
+
+int closedir_cached(DIRCACHED* dir)
+{
+    dir->busy=false;
+    if (!dircache_initialized && dir->regulardir != NULL)
+        return closedir(dir->regulardir);
+    
+    return 0;
+}
+
+#endif /* HAVE_DIRCACHE */
+